This is what works for me:
You could try adding chia seeds to water or juice and making a gel.
Add 1 tablespoon of dry seeds in 100mls of water or juice. Stir and thoroughly mix together. Wait for 10 minutes and stir again. It will then resemble a mucilage gelatinous mix of gel soft seeds.
This bulks up inside and helps to soften the stool, it then will slide and gently push the bowel movement out.
It also works well for diarrhea by absorbing loose watery stools and producing a proper well formed stool for passing.
Chia seed gel is an excellent food supplement because it is loaded with nutrients like calcium, boran, niacin, magnesium, zinc and iron. They also contain protein. Plus they contain mucin; which reduces inflammation within the digestive tract.
Constipation can be a side effect of some medication. But it can also be caused by simple dehydration.
How much pure plain water are you drinking a day?
Last time I had constipation, I simply drank about 2 - 3 litres of water throughout the day for three consecutive days, and it certainly got things moving.
Go very careful with pharmaceutical laxatives as they can be dangerous. You can easily and quickly become dependent on them. They can produce a "lazy bowel".
Found this online that explains it better than I can:
"Stimulant laxatives often times use toxic and harsh herbs and chemicals in their formulae. Stimulant laxatives work by causing intestinal muscles to spasm and contract. People are drawn to these because they usually take effect in hours as opposed to days. With these laxatives you run into the same danger as osmotic laxatives. The gas-related pain and dehydration are possible. Another danger is that they are very highly addictive and overuse and cause long-term damage to your intestinal lining. After using these laxatives for a while your intestines will grow dependent upon them and will require them to have any bowel movement. The condition is called "Lazy Bowel Syndrome", and it is basically having loss of bowel muscle tone and strength. As a result of this condition you can expect to have chronic constipation".
http://www.globalhealingcenter.com/health-hazards-to-know-about/stimulant-laxatives